This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. PropreO is an ontology that that provides the conceptual basis for semantic annotation of experimental glycoproteomics data, thereby providing a semantic framework for semantic data classification, annotation, retrieval and provenance. ProPreO also provides a framework for the automated discovery of relevant Web Services for processing glycoproteomics data.